1. Field of the Invention
The present invention relates to an image pickup apparatus, an image processing apparatus, an image pickup method, and an image processing method and, more particularly, to an image pickup apparatus, an image processing apparatus, an image pickup method, and an image processing method for obtaining a blur-emphasized image by synthesizing a plurality of images the focal positions of which differ from each other.
2. Description of the Related Art
There has heretofore been practiced a photographing method in photography wherein the focus is placed only on a main subject and portions other than the main subject are intentionally defocused by setting the aperture to a full-aperture side and thereby decreasing the depth of field. However, such a photographing method as described above is only possible with a large-sized camera, such as a single-lens reflex camera the aperture of which is manually adjustable. In addition, since the image pickup element of a compact camera or the like is small, it has been difficult to defocus portions other than a main subject even if the aperture is automatically controlled to a full-aperture side.
Hence, there is known a technique to obtain a blur-emphasized image by performing image processing on photographed image data, in order to solve the above-described problems. Japanese Patent Application Laid-Open No. 2006-140594 discloses a digital camera in which an out-of-focus area is detected from the photographed image data to perform blurring process on the out-of-focus area by means of digital signal processing. According to the digital camera described in Japanese Patent Application Laid-Open No. 2006-140594, it is possible to obtain an image, like an image photographed with a decreased depth of field, in which portions other than a main subject are intentionally blurred by means of blurring process, even when an increased depth-of-field image is photographed.